While many believe that DuPont CEO Ellen Kullman was “pushed out” of the company for fighting activist investor Nelson Peltz, a source has come out to reveal that it was Kullman’s own decision to leave her job.

According to Fortune, a source revealed early this week that Ellen Kullman left her post at the chemical giant on her own despite being with the company for almost thirty years and running it for almost seven years and in spite of winning the fight against Peltz. 

The decision for Kullman and DuPont to part ways was reportedly finalized Thursday last week but was only announced on Monday, with the source stating that the decision was mutual between Ellen and the board members.

The 59-year-old's retirement from the 213-year-old company has prompted the board members to put Edward Been on interim starting Oct. 16.

However, Suntrust Robinson Humphrey Inc. analyst Jim Sheehan opined that Kullman was removed because of the company's failure to realize its full-year projection.

Sheehan said, "They clearly needed a sacrificial lamb. You wouldn't have a CEO step aside with only a couple weeks notice without a successor in place unless it was unplanned," as quoted by Bloomberg. 

Ellen Kullman became DuPont's CEO in 2009. She is the first female CEO of the company and was tapped to play the part amid the recession. Her biggest contribution would be the acquisition of food-ingredient maker Danisco A/S and the transformation of DuPont by shedding the chemicals and auto paint businesses. 

In the final months leading to her recently announced retirement, she fought against major shareholder and activist investor Nelson Peltz, who as per Washington Post insisted that Train Fund should have more influence at DuPont because the chemical giant was not delivering the right kind of performance than its potential.